Technical Field
Aspects of the present disclosure relate to a liquid discharge head, a liquid discharge device, and a liquid discharge apparatus, and an image forming apparatus.
Related Art
An image forming apparatus includes, for example, a charging member to charge a surface of a latent image bearer while rotating, a charging power supply to output the voltage to be applied to the charging member, and a latent-image writer to write a latent image on the surface of the latent image bearer charged by the charging member.
For example, an image forming apparatus includes a charging roller as the charging member to charge a photoconductor as the latent image bearer in contact with the photoconductor. When no image forming operation is performed, the image forming apparatus detaches the charging roller from the photoconductor and brings the charging roller into contact with a conductive roller. Then, while rotating the charging roller and the conductive roller, the image forming apparatus detects electric current flowing between the charging roller and the conductive roller and uneven electric resistance in a direction of rotation of the charging roller based on the results of detection. When the magnitude of the uneven electric resistance is greater than a predetermined value, the image forming apparatus creates change pattern data to change the voltage to be applied to the charging member, according to a predetermined pattern. While rotating the charging roller, the image forming apparatus changes the output value from the power supply according to the change pattern data. Changing the output value is performed in order to reduce the uneven electric resistance of the charging roller and prevent uneven image density due to the uneven electric resistance.